One thing I've noticed recently is that mitered borders really make a huge visual difference. Miters fade into the background in a way that straight borders don't. Since the border reads solid here's what I'd try - pin the quilt to your design wall or place it on the floor and lay the borders out straight and look through your camera (or stand way back or look through a reducing lens or something to give you some visual difference) to see how the borders read. Then miter the borders, look through the camera. See what's different and think about what the is quilt calling for.
If you're thinking of entering the quilt into a show, then miter the borders. It doesn't take that much longer or that much extra fabric to accomplish this detail.
If this quilt is for personal use only, then give consideration to how much detail you want to put into the quilt. If mitering the borders makes you happy overall, then do the miter.
Happy quilting!
teri